| Main Entry: | immutable |
| Part of Speech: | adjective |
| Definition: | unchangeable |
| Synonyms: | abiding, ageless, changeless, constant, enduring, fixed, immovable, inflexible, invariable, permanent, perpetual, sacrosanct, stable, steadfast, unalterable, unmodifiable |
| Antonyms: | alterable, changeable, flexible, mutable, variable |
| Main Entry: | timeless |
| Part of Speech: | adjective |
| Definition: | eternal |
| Synonyms: | abiding, ageless, always, amaranthine, constant, continual, continued, dateless, deathless, endless, enduring, everlasting, forever, illimitable, immemorial, immortal, indefinite, infinite, lasting, never-ending, perennial, permanent, perpetual, persistent, undying, unending, without end |
| Main Entry: | sempiternal |
| Part of Speech: | adjective |
| Definition: | eternal |
| Synonyms: | abiding, ageless, always, amaranthine, boundless, ceaseless, constant, continual, continued, continuous, dateless, deathless, enduring, everlasting, forever, illimitable, immemorial, immortal, immutable, imperishable, incessant, indefinite, indestructible, infinite, interminable, lasting, never-ending, perdurable, perennial, permanent, perpetual, persistent, relentless, termless, timeless, unbroken, unceasing, undying, unending, unfading, uninterrupted, unremitting, without end |